Good...I'm glad to hear it. I take back my criticism, based on earlier reporting, whilst recognising that Professor Witty himself acknowledged that there is a debate "raging" (his word) in the scientific community over the 12 week gap. The efficacy is basically reliant on the virus ability to mutate sufficiently in the 12 week interim to render the second dose ineffective. So it is a gamble because nobody knows for sure, but one where the odds are stacked in our favour that enough people will be protected.
That said they also acknowledge that the more you vaccinate, the more it effectively forces the virus to evolve and we may need many more variants/newly developed vaccines to make it effective for all. I think I'm right in saying that the further good news is that because it is a mRNA vaccine, it makes this much easier to modify to deal with mutations... but I may have misunderstood....